 
 (comment (wcar {} (car/ping) (extend-exists nil ["k1" "invalid" "k3"])))
 
+(def ^:private k-evictable "carmine:tundra:evictable")
 (defn- extend-exists-missing-ks [ttl-ms ks & [only-evictable?]]
   (let [existance-replies (->> (extend-exists ttl-ms ks)
                                (car/with-replies) ; Single bulk reply

    datastore     - Storage for frozen key data. Default datastores:
                    `taoensso.carmine.tundra.faraday/faraday-datastore`
                    `taoensso.carmine.tundra.s3/s3-datastore`.
    :freezer      - Optional. Preps key data to/from datastore. May provide
                    services like compression and encryption, etc. Defaults to
                    Nippy with default options (Snappy compression and no

      nil))

  (worker [tstore conn wopts]
    (let [{:keys [tqname redis-ttl-ms]} opts
          {:keys [nattempts retry-backoff-ms]
           :or   {nattempts 3
                  retry-backoff-ms mq/exp-backoff}} wopts]
